Still, 
I don't know Monaco from Macau - But I work on different things all the time. 
Look in the battery compartment.  Do any of the cables go to a large block you do not recognize?  That may well be a system fuse.  It need not have actually blown, I have known of several that just got loose and quit.  Cleaning and tightening was all that was required.  This is usually close to the batteries.  
Next pull and shake every cable and make sure none are loose.
Find the 12V distribution panel.
Look for the large cable that feeds it and make sure it is solid.  
Most all the new converters have fuses.  If you were doing something like running slides when things went bad, the fuses in that could have gone.  
Well, past this we need a meter or a good test test light.  
If you don't have any meter, stop by Hazard Fright and get the cheapest.  That will still beat nothing.  
Matt